Egyptian security sources say some 36 Muslim Brotherhood supporters died today in a prison riot at the Abu Zaabal prison near Cairo while trying to escape after taking a police officer hostage. One source says the prisoners were overcome and died of vast quantities of tear gas when gunmen attacked a police convoy transferring a large group of Brotherhood prisoners who tried to escape. And a third, that the prisoners were found dead after being confined for hours in a stifling hot police truck on their way to prison.